Venturestar

VentureStar was a proposed design for a single-stage-to-orbit reusable launch
system. Lockheed Martin's
Venturestar was to be the full scale commercial version of the X-33.
Unfortunately the X-33 was cancelled in 2001. Venturestar was seen as a possible
successor to the Space
Shutle.

Venturestar was going to use Aerospike Engines.

The VentureStar vehicle was
designed to place up to 50,000 lb of payload in a LEO orbit and 15,000 lb in a
GTO orbit.

Specs:

Height 38.7 m(127 ft)
Mass 116573 kg (257,000 lb)

Reference:

Picture from
http://www.abcnews.go.com/sections/science/DailyNews/nasa_x33_990826.html